細(xì)胞計(jì)數(shù)板使用方法-文庫吧資料
2025-04-14 01:46本頁面
【正文】 r power objectives, since the counting chamber is much thicker than a conventional slide. The chamber or an objective lens may be damaged if the user is not not careful. One entire grid on standard hemacytometers with Neubauer rulings can be seen at 40x (4x objective). The main divisions separate the grid into 9 large squares (like a tictactoe grid). Each square has a surface area of one square mm, and the depth of the chamber is mm. Thus the entire counting grid lies under a volume of mmcubed Suspensions should be dilute enough so that the cells or other particles do not overlap each other on the grid, and should be uniformly distributed. To perform the count, determine the magnification needed to recognize the desired cell type. Now systematically count the cells in selected squares so that the total count is 100 cells or so (number of cells needed for a statistically significant count). For large cells this may mean counting the four large corner squares and the middle one. For a dense suspension of small cells you may wish to count the cells in the four 1/25 sq. mm corners plus the middle square in the central square. Always decide on a specific counting patter to avoid bias. For cells that overlap a ruling, count a cell as in if it overlaps the top or right ruling, and out if it overlaps the bottom or left ruling.此外，當(dāng)病人急性嚴(yán)重貧血時(shí)網(wǎng)織紅細(xì)胞可提前大量釋放，也給紅細(xì)胞計(jì)數(shù)帶來一定的干擾，而且影響網(wǎng)織紅細(xì)胞絕對(duì)值計(jì)算結(jié)果。②在高倍鏡下計(jì)數(shù)時(shí)，避開有核細(xì)胞。方法是：①實(shí)際RBC=計(jì)得RBCWBC。事實(shí)上Berkson還通過實(shí)驗(yàn)證明，紅細(xì)胞的計(jì)數(shù)域誤差為s= ，較理論誤差（Poisson分布誤差）要小。對(duì)于紅細(xì)胞計(jì)數(shù)而言，由于紅細(xì)胞數(shù)量較多，在計(jì)數(shù)室中顯得比較“擁擠”，根據(jù)Poisson公式（ ）推斷， ?？s小這種誤差的有效方法就是盡量擴(kuò)大細(xì)胞計(jì)數(shù)范圍和計(jì)數(shù)數(shù)目，一般先進(jìn)行誤差估計(jì)，然后決定所需計(jì)數(shù)的數(shù)目和計(jì)數(shù)范圍
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